Gets or sets a matrix that transforms the PhysicsShapeGroup2D vertices from local space into world space.
When retrieving a PhysicsShapeGroup2D via Rigidbody2D.GetShapes or Collider2D.GetShapes, this matrix will be set to the pose of the Rigidbody2D unless a Rigidbody2D is not available in which case the matrix it set to Matrix4x4.identity.